Influence of rheumatoid factor on serum drug levels of TNF inhibitors with different structures in rheumatoid arthritis.

OBJECTIVES: Certolizumab pegol (CZP), an Fc-free antibody fragment, has shown stable serum levels and steady efficacy in the treatment of RA patients, irrespective of RF levels at baseline. Here, we examine, in clinical practice, the effect of baseline RF and ACPA levels on serum drug levels of IFX, ADL and CZP an Fc-free antibody fragment. METHODS: This is a retrospective study performed in real-world patients. We assessed 170 patients with RA: 90 (53%) received IFX, 48 (28%) ADL and 32 (19%) CZP. Demographic and clinical variables, RF and ACPA levels were obtained at the baseline visit (T0), and patients were stratified based on negative, low, medium, or high levels. After 6 months (T6) serum drug levels and anti-drug antibodies (ADAb), were computed. RESULTS: While CZP serum levels did not differ across RF groups at T6, high baseline RF was linked to lower serum drug levels compared to RF negative status in treatment with complete monoclonal antibodies IFX and ADL. No differences in disease activity measured by DAS28 at baseline were observed across RF quartiles in patients treated with IFX or ADL. ADAb was observed in 26 patients with IFX, 3 with ADL and 1 with CZP, following 6 months of treatment. Patients with high baseline RF levels dropped out more frequently by secondary non-response in IFX or ADL than CZP (80% vs. 75% vs. 33%, p=0.002). CONCLUSIONS: In this real word data evaluation, CZP serum levels were independent of RF levels in patients however patients with high baseline RF levels who obtained IFX or ADL had lower serum drug levels at 6 months than baseline RF-negative patients. In addition, secondary non-response was more frequent in patients with high RF levels treated with IFX and ADL.

Predicting anti-TNF treatment response in rheumatoid arthritis: An artificial intelligence-driven model using cytokine profile and routine clinical practice parameters.

Introduction: Rheumatoid arthritis (RA) is a heterogeneous disease in which therapeutic strategies used have evolved dramatically. Despite significant progress in treatment strategies such as the development of anti-TNF drugs, it is still not possible to differentiate those patients who will respond from who will not. This can lead to effective-treatment delays and unnecessary costs. The aim of this study was to utilize a profile of the patient's characteristics, clinical parameters, immune status (cytokine profile) and artificial intelligence to assess the feasibility of developing a tool that could allow us to predict which patients will respond to treatment with anti-TNF drugs. Methods: This study included 38 patients with RA from the RA-Paz cohort. Clinical activity was measured at baseline and after 6 months of treatment. The cytokines measured before the start of anti-TNF treatment were IL-1, IL-12, IL-10, IL-2, IL-4, IFNg, TNFa, and IL-6. Statistical analyses were performed using the Wilcoxon-Rank-Sum Test and the Benjamini-Hochberg method. The predictive model viability was explored using the 5-fold cross-validation scheme in order to train the logistic regression models. Results: Statistically significant differences were found in parameters such as IL-6, IL-2, CRP and DAS-ESR. The predictive model performed to an acceptable level in correctly classifying patients (ROC-AUC 0.804167 to 0.891667), suggesting that it would be possible to develop a clinical classification tool. Conclusions: Using a combination of parameters such as IL-6, IL-2, CRP and DAS-ESR, it was possible to develop a predictive model that can acceptably discriminate between remitters and non-remitters. However, this model needs to be replicated in a larger cohort to confirm these findings.

Early monitoring of anti-infliximab antibodies by drug-tolerant assay predicts later immunogenicity and drug survival in rheumatic diseases.

OBJECTIVES: To investigate the appearance of anti-drug antibodies (ADA) against infliximab (IFX) determined by drug-sensitive and drug-tolerant assays and their relationship with drug levels and drug survival. METHODS: This longitudinal observational study included 45 patients with rheumatoid arthritis (RA) and 61 with spondyloarthritis (SpA). Serum samples were obtained at weeks 2, 6, 12, 24, and 52. Serum IFX levels were measured by a capture enzyme-linked immunosorbent assay (ELISA) and ADA by an in-house drug-sensitive two-site (bridging) enzyme-linked immunosorbent assay (bELISA) and a commercially available drug-tolerant ELISA (IDK, Immundiagnostik, Germany). RESULTS: Anti-drug antibodies were detected earlier by IDK than by bELISA. Once ADA appeared, positivity persisted throughout the study period. Patients who were bELISA ADA+ had higher IDK ADA levels (than bELISA ADA- patients). Circulating IFX levels were detected in all patients except those found to be bELISA ADA+. Serum IFX levels were lower in IDK ADA+ than in IDK ADA-patients.Most patients (64%) discontinued due to inefficacy. The early onset of immunogenicity was related to IFX survival. Both in RA and SpA, the median survival (years) was shorter in patients with earlier development of ADA (IDK+ before or at week 24) than those who became IDK+ later (after week 24) or never developed ADA. CONCLUSION: A drug-tolerant assay detects ADA during IFX therapy earlier and more frequently than a drug-sensitive assay. The onset of immunogenicity detected by drug-tolerant assays is related to the subsequent detection of ADA by drug-sensitive assays and drug survival.

EULAR points to consider for therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases.

OBJECTIVE: To develop EULAR points-to-consider for therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases (RMDs). METHODS: The points-to-consider were developed in accordance with EULAR standardised operation procedures by a multidisciplinary task force from eight European countries, based on a systematic literature review and expert consensus. Level of evidence and strength of the points-to-consider were determined, and mean levels of agreement among the task force were calculated using a 10-point rating scale. RESULTS: Six overarching principles and 13 points-to-consider were formulated. The level of agreement among the task force for the overarching principles and points-to-consider ranged from 8.4 to 9.9.The overarching principles define TDM and its subtypes, and reinforce the underlying pharmacokinetic/pharmacodynamic principles, which are relevant to all biopharmaceutical classes. The points-to-consider highlight the clinical utility of the measurement and interpretation of biopharmaceutical blood concentrations and antidrug antibodies in specific clinical scenarios, including factors that influence these parameters. In general, proactive use of TDM is not recommended but reactive TDM could be considered in certain clinical situations. An important factor limiting wider adoption of TDM is the lack of both high quality trials addressing effectiveness and safety of TDM and robust economic evaluation in patients with RMDs. Future research should focus on providing this evidence, as well as on further understanding of pharmacokinetic and pharmacodynamic characteristics of biopharmaceuticals. CONCLUSION: These points-to-consider are evidence-based and consensus-based statements for the use of TDM of biopharmaceuticals in inflammatory RMDs, addressing the clinical utility of TDM.

Serum leptin concentration is associated with the attainment of clinical outcomes in patients with axial spondyloarthritis treated with TNF inhibitors.

OBJECTIVES: To analyse the influence of adipokines on attaining the clinical outcomes in patients with axial spondyloarthritis (axSpA) treated with TNF inhibitors (TNFi), and then, to investigate the association of patients' characteristics and adipokine concentrations. METHODS: This was a longitudinal study including 110 patients with axSpA who were initiated at TNFi and were followed-up for 6 months (m). Disease activity was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) at baseline and at 6 m of treatment. Clinical outcomes at 6 m of treatment were defined as remission (ASDAS <1.3) and the attainment of low disease activity (LDA; ASDAS<2.1). Leptin and adiponectin concentrations were measured in serum samples collected at baseline and after 6 m. RESULTS: Both leptin and adiponectin were constitutively elevated in female axSpA patients. At time of TNFi initiation, leptin concentrations were higher in patients with high body mass index (overweight or obese). On the contrary, adiponectin was higher in normalweight patients. After 6 m of TNFi treatment, 24% of patients attained remission. They had significant lower leptin concentration at baseline compared with patients who did not attain remission. Furthermore, this difference remained significant after 6 m of treatment meaning that TNFi did not modify adipokine concentration. Similar results were found considering LDA as the clinical outcome, obtained in 48% of the patients. CONCLUSIONS: The present study showed that low leptin concentrations were associated with attaining clinical outcomes in axSpA patients treated with TNFi. In addition, since leptin secretion by white adipocytes is enhanced during obesity and considering that TNFi do not seem to modulate its expression, obese patients should be encouraged to decrease BMI to attain a successful therapy.

Low Serum BAFF Concentration Is Associated with Response to TNF Inhibitors in Seropositive Patients with Rheumatoid Arthritis.

We investigated B-cell-activating factor (BAFF) in relation to response to treatment with TNF inhibitors (TNFis) in rheumatoid arthritis (RA). This was a longitudinal study including 158 patients with RA treated with TNFis and followed up for 6 months. Clinical response at 6 months of treatment was defined according to the EULAR criteria for good responders (GRs). BAFF concentration was measured in serum samples, collected at baseline and at 6 months. Associations with EULAR response were evaluated using univariable and multivariable logistic regression models. ROC analysis was performed to determine the optimal threshold of serum BAFF concentration associated with good EULAR response to treatment. After 6 months of TNFi treatment, 24% of patients were GRs. They had a lower BMI, lower baseline DAS28 and lower baseline serum BAFF concentration than non-responders. After 6 months of TNFi treatment, autoantibody-positive patients who attained GR had significantly lower serum BAFF concentrations compared with patients who did not. Serum BAFF < 968 pg/mL at 6 months represented the concentration likely to best discriminate between GR and non-GR at 6 months of TNFi treatment. Autoantibody-seropositive patients who had serum BAFF < 968 pg/mL at 6 months demonstrated a more than four-fold increased probability to be GRs compared with patients with higher BAFF concentrations. In conclusion, serum BAFF concentrations were associated with response to TNFis in seropositive RA patients, corroborating the importance of the B-cell compartment in RA.

Therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal disease: a systematic literature review informing EULAR points to consider.

The objectives of this review were to collect and summarise evidence on therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases and to inform the EULAR Task Force for the formulation of evidence-based points to consider. A systematic literature review (SLR) was performed, covering technical aspects and (clinical) utility of TDM, to answer 13 research questions. MEDLINE, Embase and Cochrane were searched until July 2020. American College of Rheumatology and EULAR abstracts were also considered for inclusion. Data were extracted in evidence tables and risk of bias assessment was performed. For the search on technical aspects, 678 records were identified, of which 22 papers were selected. For the clinical utility search, 3846 records were identified, of which 108 papers were included. Patient-related factors associated with biopharmaceutical blood concentrations included body weight, methotrexate comedication and disease activity. The identification of a target range was hampered by study variability, mainly disease activity measures and study type. Evidence was inconsistent for multiple clinical situations in which TDM is currently applied. However, for some particular scenarios, including prediction of future treatment response, non-response to treatment, tapering and hypersensitivity reactions, robust evidence was found. There is currently no evidence for routine use of proactive TDM, in part because published cost-effectiveness analyses do not incorporate the current landscape of biopharmaceutical costs and usage. This SLR yields evidence in favour of TDM of biopharmaceuticals in some clinical scenarios, but evidence is insufficient to support implementation of routine use of TDM.

Evaluation of AIF-1 (Allograft Inflammatory Factor-1) as a Biomarker of Crohn's Disease Severity.

Background: Recently, increased tissue levels of AIF-1 have been shown in experimental colitis, supporting its role in intestinal inflammation. Therefore, we studied the levels of AIF-1 in Crohn's disease (CD). Methods: This study included 33 patients with CD (14 men and 19 women) who participated in the PREDICROHN project, a prospective multicenter study of the Spanish Group of Inflammatory bowel disease (GETECCU). Results: This article demonstrates declines with respect to baseline levels of serum AIF-1 in Crohn's disease (CD) patients after 14 weeks of treatment with anti-TNFs. Furthermore, in patients with active CD (HB ≥ 5), serum AIF-1 levels were significantly higher than those in patients without activity (HB ≤ 4). The study of serum AIF-1 in the same cohort, revealed an area under the ROC curve (AUC) value of AUC = 0.66 (p = 0.014), while for the CRP (C-reactive protein), (AUC) value of 0.69 (p = 0.0066), indicating a similar ability to classify CD patients by their severity. However, the combination of data on serum levels of AIF-1 and CRP improves the predictive ability of these analyses for classifying CD patients as active (HB ≥ 5) or inactive (HB ≤ 4). When we used the odds ratio (OR) formula, we observed that patients with CRP > 5 mg/L or AIF-1 > 200 pg/mL or both conditions were 13 times more likely to show HB ≥ 5 (active CD) than were those with both markers below these thresholds. Conclusion: The development of an algorithm that includes serum levels of AIF-1 and CRP could be useful for assessing Crohn's disease severity.

Obesity and response to biological therapy in rheumatoid arthritis: the role of body mass index and adipose tissue cytokines.

OBJECTIVES: To analyse the role of body mass index (BMI) in the clinical response to biologic dis-ease-modifying anti-rheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA). To per-form an in-depth analysis of the pathophysiology of obesity by assessing serum adipokine levels and their potential changes according to treatment. METHODS: This study involved 105 patients with RA starting tumour necrosis factor inhibitors (TNFi) or tocilizumab (TCZ). Patients were classified ac-cording to BMI as normal-weight and overweight/obesity. The clinical response to treatment was as-sessed by Clinical Disease Activity Index (CDAI) 6 months after initiation of bDMARDs. Serum adi-pokines (leptin and adiponectin) were determined using a commercial immunoassay kit in samples ob-tained before initiation of bDMARDs and after 6 months of treatment. RESULTS: A correlation was observed between BMI and disease activity and between BMI and serum adipokines. Sixty percent of patients achieved low disease activity (LDA)/remission: 45 patients in TNFi group (64.2%) and 18 (51.4%) in TCZ group. In TNFi group, patients who did not attain LDA/remission had a higher BMI (kg/m2) ([28.7±5.1] vs. [24.5±4.6], p=0.001) and baseline CDAI (26.3 [17.4-33.9] vs. 19.8 [14.0-28.8], p<0.03). However, no differences in BMI or baseline CDAI were observed between patients who achieved LDA after 6 months in TCZ group. CONCLUSIONS: Obesity influences the extent of LDA/remission in patients treated with TNFi, but not in patients treated with TCZ, probably because of underlying pathophysiological mechanisms intrinsic to the production of proinflammatory adi-pokines. Therefore, therapeutic strategies with a mechanism of action other than TNF inhibition would be more suitable for obese patients.

Comparison of long-term efficacy between biological agents following tumor necrosis factor inhibitor failure in patients with rheumatoid arthritis: a prospective cohort study.

BACKGROUND: Currently, there is contradictory evidence regarding the best strategy to follow after discontinuation of a first biological agent in patients with rheumatoid arthritis (RA). We aimed to compare the long-term efficacy of switching to a second tumor necrosis factor inhibitor (TNFi) versus biopharmaceuticals with other mechanisms of action (non-TNFi) in patients with RA who previously failed a first TNFi. METHODS: This prospective cohort study analyzed data from 127 patients who discontinued a previous TNFi between 1999 and 2016. Disease activity was assessed at baseline and at 6, 12, and 24 months (m-6, m-12, m-24) after switching. Primary outcome was the proportion of patients achieving good/moderate EULAR response (E-resp). Factors associated with clinical outcomes were assessed using univariate and multivariate logistic regression models. RESULTS: Seventy-seven (61%) patients received a second TNFi and 50 (39%) switched to a non-TNFi. At m-6 and m-12, no differences were observed between groups; nevertheless, at m-24, the proportion of patients with E-resp was higher in the non-TNFi group (49% TNFi group versus 77% non-TNFi group; p = 0.002). In regression models, switching to a non-TNFi was significantly associated with E-resp at m-24 (odds ratio = 3.21; p = 0.01). When assessing the response to the second biological agent based on the reason for discontinuation of the first TNFi, similar results were obtained; at m-24, patients who discontinued the first TNFi due to inefficacy (either primary or secondary) experienced a better E-resp if they had switched to a non-TNFi (primary inefficacy: 52% TNFi group versus 79% non-TNFi group, p = 0.09; secondary inefficacy: 50% versus 76%, p = 0.03). CONCLUSION: In our cohort of RA patients who discontinued a first TNFi, those who switched to a non-TNFi were three times more likely to attain a sustained clinical response, regardless of whether they had discontinued the first biologic due to a primary or secondary inefficacy.

Relationship between IGF-1 and body weight in inflammatory bowel diseases: Cellular and molecular mechanisms involved.

Inflammatory bowel diseases (IBD), represented by ulcerative colitis (UC) and Crohn's disease (CD), are characterized by chronic inflammation of the gastrointestinal tract, what leads to diarrhea, malnutrition, and weight loss. Depression of the growth hormone-insulin-like growth factor-1 axis (GH-IGF-1 axis) could be responsible of these symptoms. We demonstrate that long-term treatment (54 weeks) of adult CD patients with adalimumab (ADA) results in a decrease in serum IGF-1 without changes in serum IGF-1 binding protein (IGF1BP4). These results prompted us to conduct a preclinical study to test the efficiency of IGF-1 in the medication for experimental colitis. IGF-1 treatment of rats with DSS-induced colitis has a beneficial effect on the following circulating biochemical parameters: glucose, albumin, and total protein levels. In this experimental group we also observed healthy maintenance of colon size, body weight, and lean mass in comparison with the DSS-only group. Histological analysis revealed restoration of the mucosal barrier with the IGF-1 treatment, which was characterized by healthy quantities of mucin production, structural maintenance of adherers junctions (AJs), recuperation of E-cadherin and ß-catenin levels and decrease in infiltrating immune cells and in metalloproteinase-2 levels. The experimentally induced colitis caused activation of apoptosis markers, including cleaved caspase 3, caspase 8, and PARP and decreases cell-cycle checkpoint activators including phosphorylated Rb, cyclin E, and E2F1. The IGF-1 treatment inhibited cyclin E depletion and partially protects PARP levels. The beneficial effects of IGF-1 in experimental colitis could be explained by a re-sensitization of the IGF-1/IRS-1/AKT cascade to exogenous IGF-1. Given these results, we postulate that IGF-1 treatment of IBD patients could prove to be successful in reducing disease pathology.

Remission Induced by TNF Inhibitors Plus Methotrexate is Associated With Changes in Peripheral Naïve B Cells in Patients With Rheumatoid Arthritis.

Biological therapies, such as TNF inhibitors (TNFi), are increasing remission (REM) rates in rheumatoid arthritis (RA) patients, although these are still limited. The aim of our study was to analyze changes in the profile of peripheral blood mononuclear cells (PBMC) in patients with RA treated with TNFi in relation to the clinical response. This is a prospective and observational study including 78 RA patients starting the first TNFi. PBMC were analyzed by flow cytometry both at baseline and at 6 months. Disease activity at the same time points was assessed by DAS28, establishing DAS28 ≤ 2.6 as the criteria for REM. Logistic regression models were employed to analyze the association between the changes in PBMC and REM. After 6 months of TNFi treatment, 37% patients achieved REM by DAS28. Patients who achieved REM showed a reduction in the percentage of naive B cells, but only when patients had received concomitant methotrexate (MTX) (OR: 0.59; 95% CI: 0.39-0.91). However, no association was found for patients who did not receive concomitant MTX (OR: 0.85; 95% CI: 0.63-1.16). In conclusion, PBMC, mainly the B-cell subsets, are modified in RA patients with TNFi who achieve clinical REM. A significant decrease in naive B-cell percentage is associated with achieving REM after 6 months of TNFi treatment in patients who received concomitant therapy with MTX.

Methotrexate Reduces the Probability of Discontinuation of TNF Inhibitors in Seropositive Patients With Rheumatoid Arthritis. A Real-World Data Analysis.

Tumor necrosis factor inhibitors (TNFi) are widely used for the treatment of patients with rheumatoid arthritis (RA), however a considerable percentage of patients discontinued the therapy. The aim of this study is to explore real-world TNFi survival, stratified for seropositivity, and to determine the factors that may influence it. This is a retrospective, observational and longitudinal study, using real-world data of patients, who started their first TNFi therapy between 1999 and 2018 from the RA-PAZ cohort. Patients were considered seropositive if they showed positive serum levels of either RF, ACPA, or both. Treatment survival was analyzed using Kaplan-Meier curves, and Cox proportional hazards models were used to compare the risks of TNFi discontinuation for seronegative and seropositive patients. Of the included 250 patients, 213 (85%) were seropositive. Results showed that TNFi survival did not depend on seropositivity status. However, median survival time was significant longer for seropositive patients who received concomitant MTX compared to patients who did not receive it (median [95% CI]: 3.3 yr. [2.3-4.2] vs. 2.6 yr. [1.7-3.6], respectively; p = 0.008). Furthermore, seropositive patients who received concomitant MTX were 49% less likely to discontinue TNFi therapy than patients who did not receive it (HR: 0.51; 95% CI: 0.35-0.74). In addition, we found that in seropositive patients, the use of prednisone throughout the TNFi treatment was associated with a higher likelihood of therapy discontinuation (OR: 2.30; 95% CI: 1.01-5.23). In conclusion, these data provide evidence to support the use of concomitant MTX in seropositive patients to prolong the effectiveness and the survival of the TNFi therapy. Moreover, the co-administration of prednisone in seropositive patients receiving TNFi was highly associated with TNFi discontinuation.

BAFF predicts immunogenicity in older patients with rheumatoid arthritis treated with TNF inhibitors.

Immunogenicity related to treatment with TNF inhibitors (TNFi) is one of the causes for the decreased attainment of clinical response in patients with rheumatoid arthritis (RA). The B-cell activating factor (BAFF) may be playing a role in the development of immunogenicity. The objective of this study was to analyse the association of baseline concentration of serum B-cell activating factor (BAFF) with immunogenicity after 6 months of TNFi treatment. A total of 127 patients with RA starting a TNFi (infliximab, adalimumab, certolizumab pegol or golimumab) were followed-up for 6 months. Serum samples were obtained at baseline and at 6 months and anti-drug antibody (ADA) and BAFF concentrations were measured. Logistic regression models were employed in order to analyse the association between BAFF concentrations and immunogenicity. Receiver operating characteristic analysis was performed to determine the BAFF concentrations with a greater likelihood of showing immunogenicity association. At 6 months, 31 patients (24%) developed ADA. A significant interaction between the age and baseline BAFF concentration was found for the development of ADA (Wald chi-square value = 5.30; p = 0.02); therefore, subsequent results were stratified according to mean age (≤ / > 55 years). Baseline serum BAFF concentration was independently associated with ADA development only in patients over 55 years (OR = 1.51; 95% CI 1.03-2.21). Baseline serum BAFF ≥ 1034 pg/mL predicted the presence of ADA at 6 months (AUC = 0.81; 95% confidence interval (CI) 0.69-0.93; p = 0.001; positive likelihood ratio = 3.7). In conclusion, our results suggest that the association of BAFF concentration and immunogenicity depends on the patient's age. Baseline serum BAFF concentration predicts the presence of ADA within 6 months of TNFi therapy in older patients with RA.

Dendritic Nanotheranostic for the Delivery of Infliximab: A Potential Carrier in Rheumatoid Arthritis Therapy.

Antibodies are macromolecules that specifically recognize their target, making them good candidates to be employed in various therapies. The possibility of attaching a drug to an immunoglobulin makes it possible to release it specifically into the affected tissue as long as it overexpresses the target. However, chemical coupling could affect the functionality (specificity and affinity) of the antibody. It has been observed that the use of intermediaries, such as dendrimers, could resolve this issue. Because carbosilane dendrimers have aroused great interest in the field of biomedicine, this report describes the synthesis of an anionic carbosilane dendrimer with a fluorochrome on its surface that then forms a conjugate with an antibody. It has been used as immunoglobulin and infliximab, whose target is TNF-α, which is a cytokine that is overexpressed in the inflamed area or even in the blood of patients with autoimmune diseases, such as rheumatoid arthritis. In addition, the integrity and functionality of the antibody has been studied to see if they have been affected after the chemical coupling process.

Infliximab concentrations in two non-switching cohorts of patients with inflammatory bowel disease: originator vs. biosimilar.

Biosimilars are replacing originator compounds due to their similar effectiveness, safety and pharmacokinetics. Our objective was to compare the differences in pharmacokinetics and clinical outcomes between the originator infliximab (Ifx) and the biosimilar CT-P13 in a patient cohort with inflammatory bowel disease (IBD). Our cohort study included 86 patients from a historical and a prospective cohort from the start of infliximab treatment to 22 weeks later. Serum infliximab, antidrug antibody levels and other serum biomarkers were measured at weeks 0, 2, 6, 14 and 22. Remission outcomes were evaluated at weeks 14 and 22. Drug levels were measured prospectively and analysed using MANOVA. Of the 86 patients, 44 (51%) and 42 (49%) were administered the originator and CT-P13, respectively. Originator trough levels were higher than the biosimilar trough levels (35 vs. 21, 20.1 vs. 11, 6.6 vs. 2.9 and 4.3 vs. 1.7 µg/mL at weeks 2, 6, 14 and 22, respectively). A post-hoc analysis demonstrated changes in mean serum drug levels over time (p < 0.001) and according to the drug employed (p = 0.001). At week 22, 13 (81%) patients administered the originator achieved clinical remission compared with 5 (19%) patients with the biosimilar (p = 0.02). None of the patients administered the originator withdrew from the treatment compared with 7 for the biosimilar. During the study, there were significant differences in serum infliximab levels between the originator and the CT-P13 in the patients with IBD. The clinical outcomes were influenced by the type of compound administered.

Blood Lymphocyte Subsets for Early Identification of Non-Remission to TNF Inhibitors in Rheumatoid Arthritis.

Background: TNF inhibitors (TNFis) are widely used for the treatment of rheumatoid arthritis (RA), although the response rates to this therapy in patients with RA remains heterogeneous and < 50% achieve remission (REM). Objective: To analyze baseline peripheral blood leukocytes profiles in order to search for biomarkers identifying patients who will most likely not achieve REM under TNFi treatment. Methods: A prospective bi-center pilot study including 98 RA patients treated with TNFis and followed-up during 6 months. Patients were classified according to DAS28 as follows: those who achieved REM (DAS28 ≤ 2.6) and those who did not (DAS28 > 2.6) at 6 months after starting TNFis. These rates were also assessed by simplified disease activity index (SDAI ≤ 3.3 and SDAI > 3.3, respectively). Peripheral blood immune cells were studied by flow cytometry before treatment initiation. Results: At 6 months, 61 or 80% of patients did not achieve REM by DAS28 or SDAI, respectively. Basal leukocyte profiles differed between REM vs. non-REM patients. Non-REM patients showed lower percentages of total and naïve B cells at baseline than REM subjects. A B lymphocyte/CD4+ lymphocyte ratio (BL/CD4 ratio) <0.2 clearly associated with a higher probability of non-REM status based on DAS28 at 6 months (OR = 9.2, p = 0.006). These data were confirmed when patient response was evaluated by SDAI index. Conclusion: Our results strongly suggest that BL/CD4 ratio could be considered as a useful biomarker for the early identification of non-remitters to TNFi in clinical practice.

Usefulness of monitoring antitumor necrosis factor serum levels during the induction phase in patients with Crohn's disease.

AIMS: The aims of this study were (a) to know the kinetics of antitumor necrosis factor (TNF) drug serum levels during the induction phase in patients with Crohn's disease; (b) to identify variables associated with these levels; and (c) to assess the relation between these levels and short-term effectiveness in Crohn's disease patients. METHODS: Patients with Crohn's disease naïve to anti-TNF treatment were prospectively included. Remission was defined as a Crohn's disease activity index (CDAI) score <150 after 14 weeks of treatment. Blood samples were obtained at baseline and at weeks 4, 8, and 14. Adalimumab and infliximab levels were measured, receiver operating characteristic (ROC) curves were constructed, and the area under the ROC curve was calculated. RESULTS: One-hundred fifty patients with Crohn's disease were included, 79 (53%) received infliximab and 71 (47%) had CDAI > 150 at study entry. At week 14, 52 out of 71 patients with CDAI > 150 at baseline (73%) had clinical remission. There were no differences in infliximab levels between patients with and without remission (8 vs. 9.1 µg/mL, P > 0.05) or with and without response (7 vs. 11 µg/mL, P > 0.05) at week 14. There was a trend to higher levels of adalimumab concentration in responders in comparison with nonresponders (13 vs. 6.7 µg/mL, P = 0.05) and in patients who achieved remission in comparison with nonremitters (13.5 vs. 8.4 µg/mL, P = 0.06). In the multivariate analysis, no variable was predictive of short-term remission, including infliximab and adalimumab serum levels. CONCLUSION: Determining anti-TNF serum levels during the induction phase is not useful for predicting short-term remission in patients with Crohn's disease.

Extracellular allograft inflammatory factor-1 (AIF-1) potentiates Th1 cell differentiation and inhibits Treg response in human peripheral blood mononuclear cells from normal subjects.

We identified the presence of AIF-1 (allograft inflammatory factor-1) in human peripheral blood mononuclear cells (PBMCs) from normal subjects by immunocytological methods. After isolation of different types of mononuclear cells by FACS (Fluorescence-activated cell sorting) with >95% purity, we studied the transcript levels of AIF-1 using qPCR. We observed the following order of AIF-1 mRNA expression in mononuclear cells: T-lymphocytes Ëƒ Monocytes Ëƒ B-lymphocytes Ëƒ NK. After T cell expansion of isolated PBMCs using anti-CD3-CD28 magnetic beads (Dynabeads®), AIF-1 increased intracellularly in the presence of brefeldin A; this finding, along with an increase in the medium in the absence of the drug, suggests that AIF-1 is processed in the Golgi apparatus and may be secreted extracellularly. In another set of experiments, interleukin-12 and anti-interleukin-4 were added to PBMCs during T cell expansion to promote Th1 polarization and to inhibit Th2 differentiation. In this case, the presence of 6 nM of rhAIF-1 (recombinant human AIF-1) increased the mRNA expression of interferon-ϒ and interleukin-2. In the same set of experiments, the incubation of PBMCs with rhAIF-1 (6 nM) promoted the decrease of mRNA expression of IL-10 and TGF-ß, along with the decrease of CD25 and Foxp3 proteins. Furthermore, extracellular rhAIF-1 (6 nM) increased the survival of naive and effector T cells during Th1 polarization by inhibition of apoptosis, without causing changes in cell cycle rate and in retinoblastoma-cyclin-dependent kinase (Rb-CDK) activation. Taken together, rhAIF-1 treatment of PBMCs potentiates Th1 response and inhibits functionally suppressive CD25 + Foxp3 + Treg, which suggests an important immunomodulatory role in governing T cell response.